First-half goals from Aiden McGeady and Grant Leadbitter looked to have sealed the win for the Black Cats, only for the visitors to net a late leveller.
But who were the star men at the Stadium of Light?
Scroll down and click through the pages as chief football writer Phil Smith dishes out his merit marks:
1. Lee Burge
A mixed afternoon. Made one absolutely superb stop from MacDonald but was otherwise unconvincing against Gillingham’s bombardment of the box. 5 Photo: FRANK REID 2019
2. Max Power
Steady performance defensively, and did well in the air when called upon. Couldn't get forward to contribute much. 5 Photo: FRANK REID 2020
3. Jordan Willis
By far Sunderland’s best defender and deserved the win for his contribution. Did very well against a physical side, but for the most part his team-mates were unable to match that. 7 Photo: Frank Reid
4. Tom Flanagan
Recalled to the side ahead of Dion Sanderson to deal with Gillingham’s physical threat. Did OK for the most part, but it was an afternoon where Bailey Wright was clearly missed. 5 Photo: Frank Reid